Migrating from 2.0.x to 2.2.x

This guide provides instructions on how to migrate your Ktor application from the 2.0.x version to 2.2.x.

Ktor Server

Cookies

With v2.2.0, the following API members related to configuring response cookies are changed:

The maxAge parameter type passed to the append function is changed from Int to Long.
The appendExpired function is deprecated. Use the append function with the expires parameter instead.

Request address information

Starting with the 2.2.0 version, the RequestConnectionPoint.host and RequestConnectionPoint.port properties used to get the hostname/port to which the request was made are deprecated.

get("/hello") {
    val originHost = call.request.origin.host
    val originPort = call.request.origin.port
}

Use RequestConnectionPoint.serverHost and RequestConnectionPoint.serverPort instead. We've also added the localHost/localPort properties that return the hostname/port on which the request was received. You can learn more from the Original request information.

Merging configurations

Before v2.2.0, the List<ApplicationConfig>.merge() function is used to merge application configurations. In case both configurations have the same key, the resulting configuration takes the value from the first one. With this release, the following API is introduced to improve this behavior:

public fun ApplicationConfig.withFallback(other: ApplicationConfig): ApplicationConfig: this function works the same way as merge() and takes the value from the first configuration.
public fun ApplicationConfig.mergeWith(other: ApplicationConfig): ApplicationConfig: the resulting configuration takes the value from the second one.

Ktor Client

Caching: Persistent storage

With v2.2.0, the following API related to response caching is deprecated:

The HttpCacheStorage class is replaced with the CacheStorage interface, which can be used to implement a persistent storage for the required platform.
The publicStorage/privateStorage properties are replaced with corresponding functions that accept CacheStorage instances.

Custom plugins

Starting with the 2.2.0 release, Ktor provides a new API for creating custom client plugins. To learn more, see Custom plugins.

New memory model

With v2.2.0, Ktor uses the 1.7.20 version of Kotlin, in which the new Kotlin/Native memory model is enabled by default. This means that you don't need to enable it explicitly for Native server or client engines targeting Kotlin/Native.

Last modified: 02 April 2024